In Depth
Wuerhosaurus is currently the latest surviving known member of the stegosaur group. In being so, the temporal range of these kinds of dinosaurs has been significantly extended up to the middle Cretaceous, forty-five million years after their Jurassic heyday.
Unfortunately Wuerhosaurus is only represented by partial remains, making accurate reconstruction of this stegosaurid problematic. The dorsal plates were initially conceived as being ‘flat’ at the top as opposed to pointed like in so many of the others of the group, but further research has suggested that they were simply broken, giving the false impression that they were flattened. It has also been presumed that Wuerhosaurus possessed a thagomizer like other Stegosaurids, but analysis has suggested that the single spike recovered may have in fact projected from the shoulder.
The hips appear to be even wider than other stegosaurids in what is thought to accommodate a larger digestive area. The head is also carried lower to the ground for low browsing, implying that Wuerhosaurus carried the characteristic stegosaurid morphology to even greater extremes than its predecessors. Wuerhosaurus was also moderately sized for its kind with the type species, W. homheni being the larger at an estimated length of up to seven meters, with W. ordonsensis being smaller at an estimated length of up to five meters.
Some palaeontologists consider Wuerhosaurus to be synonymous with the more well-known Stegosaurus. The problem here is that Stegosaurus is known only until the Tithonian of the Jurassic, and is also from a completely different geographical location. These too reasons are often justified as enough cause to isolate two similar animals into a separate genus for each, but as is often the case, only new and more complete fossil material would be enough to prove either theory without doubt. It is not completely out of the question that Wuerhosaurus could have been a late surviving descendent of Stegosaurus.Further reading
– [Dinosaurs from Wuerho] – Z. Dong – 1973.
– A new species of stegosaur (Dinosauria) from the Ordos Basin, Inner Mongolia, People’s Republic of China – Z. Dong – 1993.
– Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia) – Susannah C.R. Maidment, David B. Norman, Paul M. Barrett & Paul Upchurch – 2008.
